Soviet calculators

They had calculators too. They were rare as manufacturing was
expensive, but some of them were exported to other eastern block
countries. Usually Soviet calculators used soviet chips which were
sometimes (but not always) clones of western circuits, for example Elka
printing calculator used original Rockwell's chip and later Soviet copy.
Parts like display tubes, diodes, capacitors, sometimes LCDs and solar
cells could be manufactured in soviet factories. Solar cells based
calculators used very small backup capacitors because larger capacities
were expensive.
In eastern block there was a permanent problem with paper for
electrolytic capacitors. Soviet Union used enormous amount of Palladium
alloys to make larger capacities. By using this precious metal they used
less paper. Poland imported "kondensatornaya bumaga" (capacitor paper)
from Soviet Union, but it was so poor in quality that they actually
started to use it in late 1980s when technology became better.

Elektronika MK-60
(Электроника МК-60)

Type

Simple pocket

Display:

LCD

Keyboard:

Membrane.

Chip:

KB145WH3A-2 (КБ145ВХ3А)

Display driver:

In a chip

Batteries:

Solar cells

Operations:

+, -, /, *, Decimal Point, %,sqrt,
memory.

The first Soviet calculator powered
by solar cells and the first solar-powered calculator in Eastern
block, manufactured since 1982 till early 1990s (?1994?). It was
promised that it'll work when exposed to 100W incandescent bulb
light in maximum distance of 2m or 60cm away from 15W
fluorescent lamp. Small, portable, simple, made with Soviet
components.

There was also MK-60M version (export version)
which had English letters on keys.